These stunning images above were all drawn in real time. These were not sketched in pencil first. No photographs were taken to freeze the frenzy that may have ensued on stage during globalFEST 2013, the annual one-night, dozen-band showcase of great up-and-coming musicians from around the world at New York City's Webster Hall last weekend.

Michael Arthur works in pen and ink and uses some brushes to get varied lines on the heavy stock watercolor paper he uses. Sometimes there are bursts of color in his otherwise black and white drawings. He doesn't sketch — what he put down while a band was on stage is what you see now. At globalFEST, he drew all 12 bands. We posted them on Twitter as he finished them, but seeing them made me curious about his process, so I called him up.

Arthur has a PhD in theater history, and has been drawing Broadway rehearsals for years. He's used to drawing fast because he knows the image on stage may vanish at any moment. He says he has a sixth sense about when that will happen. The first thing I asked him was how he was able to capture so much so fast.

"Sometimes there are moments when I think, 'Eh, I'm not going to be able to draw something.' And then suddenly I'm drawing something," he says. "Something will move me. I tend to think of it as a building. If I get someone's eye right, then I can sort of move on to their nose. And I think the music, when I'm drawing in a musical situation, sort of carries my energy. I tend to draw to the rhythm of the music."

When I asked Michael Arthur if the music affects the color of his drawings, he told me something astonishing: "I'm colorblind." That helped explain why he drew my deep black scarf the color red (you can see that drawing in the last slide above). He says he's learning to use color, something that's relatively new to him. He drew as a child, but never took lessons. He couldn't draw what he was told, but found comfort in drawing what he wanted. It's helped him get through a number of string of losses in his life, including his mom in 1999. From the quiver in his voice, I could tell that one is still tough.

His drawing career took off about five years ago when the comedian Kristin Schaal approached him to draw her while she performed at the downtown New York venue Joe's Pub. A musician who saw the drawings then asked him to do the same, and the Joe's Pub folks encouraged him to do more, promising to eventually hold a show of his drawings.

He's fine-tuned his style since then, noticed how guitarists hold their instruments differently, what their position is when they sing. Eventually, he'd collaborate with bands like Balthrop, Alabama, which had him draw its performance and projected his work onto a screen behind the band, like a live movie. He captures so much with so little; it's not too far from the way a soloist — perhaps a pianist — might work. A few notes can say a lot.